Method of operating an integrated balloon catheter inflation system

ABSTRACT

An inflation system having two pressure vessels integrated into a balloon catheter. A pressurized chamber and a vacuum chamber are integrally attached to proximal end of the balloon catheter and activated by a common valve or switch. Pressure or vacuum is selectively transmitted to the balloon depending on the valve/switch position. The working fluid may be air, or a combination of air and saline with an intermediate piston/cylinder assembly. The balloon catheter may be a part of a heart valve delivery system with a balloon-expandable heart valve crimped onto the balloon.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/469,978, filed Aug. 27, 2014, now U.S. Pat. No. 9,919,137, whichclaims the benefit of U.S. Application No. 61/871,240, filed Aug. 28,2013, the entire disclosures all of which are incorporated by reference.

FIELD OF THE INVENTION

The present invention generally relates to balloon catheters and, inparticular, to an integrated inflation system for balloon catheters.

BACKGROUND OF THE INVENTION

Balloon dilatation catheters are used for a variety of procedures inwhich a body lumen or vessel is dilated. For example, such catheters areused in percutaneous transluminal angioplasty procedures in which astenosed region of an artery, such as a coronary artery, is widened byinserting a deflated balloon into the stenosis and then inflating theballoon under pressure to forcibly enlarge the lumen through the artery.After a brief period of time, the balloon is deflated and removed. Suchcatheters typically have an elongate flexible shaft and a balloonmounted at the distal end of the shaft. The shaft has a ballooninflation lumen that provides fluid communication between the proximalend of the catheter and the interior of the balloon at the distal end ofthe shaft.

Balloon catheters are typically actuated by manual syringes, oftencalled “inflators” (or inflation devices), which use a plunger that ismanually advanced using a rod that is threaded into a handle to allowthe operator to advance the plunger using very small, controlledincrements. Some syringes include a pressure gauge, but the gauge isoften located on the syringe itself, and it therefore may be impracticalfor the physician to monitor the gauge as he or she tries to also watchan image of the balloon being inflated on a monitor. The process forsetting up and operating a manual balloon inflation syringe createslogistical difficulties.

Automatic injection devices, such as described in U.S. Pat. No.6,099,502, are known for delivering fluids such as saline and contrastagents through a catheter to a patient. The devices typically include amotor-driven linear actuator that forces a plunger through a syringe,thereby creating a desired fluid flow into the patient. For sanitationpurposes, the syringe and all associated tubing between the patient andthe syringe are disposable, which increases the expense of the system.Further, preparing the automatic injection device for operation can be atime-consuming process. Various tubes may need to be connected togetherand to the device. The operator preparing the injection device foroperation must often be careful to ensure that the connections are tightand that none of the tubes are pinched or otherwise blocked.

Although numerous configurations are available for inflating ballooncatheters, there is a need for a simpler system.

SUMMARY OF THE INVENTION

An integrated inflation system having two pressure vessels integratedinto a balloon catheter. A pressurized chamber and a vacuum chamber areintegrated within the proximal end of the balloon catheter and activatedby a common valve or switch. Pressure or vacuum is transmitted to theballoon depending on the valve/switch position.

In one embodiment, a balloon catheter system having an integratedinflation subsystem, comprises a manifold having internal passages and apressurized vessel integrated with an inflation port in the manifold. Aballoon catheter has a balloon on a distal end in fluid communicationwith an inflation lumen extending through the catheter, which in turn isin fluid communication with a balloon port in the manifold. A controlvalve on the manifold is configured to selectively open and close fluidcommunication between the balloon port and the inflation port so that apositive pressure differential from the pressurized vessel inflates theballoon. The system may further include a vacuum vessel integrated witha vacuum port in the manifold, wherein the control valve is alsoconfigured to selectively open and close fluid communication between theballoon port and the vacuum port so that a negative pressuredifferential from the vacuum vessel deflates the balloon.

In accordance with another aspect, a manufactured balloon cathetersystem includes a balloon catheter having a balloon on a distal end influid communication with an inflation lumen extending through thecatheter, and an integrated inflation system assembled and packaged withthe balloon catheter. The integrated inflation system has a manifoldwith internal passages, a pressurized vessel integrated with aninflation port in the manifold, a vacuum vessel integrated with a vacuumport in the manifold, and a balloon port in the manifold in fluidcommunication with the balloon catheter inflation lumen. Finally, acontrol valve on the manifold selectively opens fluid communicationbetween the manifold port and one or the other of the pressurized vesseland vacuum vessel.

In a preferred embodiment, the balloon catheter system is part of aprosthetic heart valve delivery system including a balloon-expandableheart valve crimped onto the balloon. Desirably, the pressurized vesseland the vacuum vessel are permanently attached to the manifold, such asvia adhesion or thermal welding. In a preferred version, the manifoldopens to just the balloon port, inflation port and vacuum port, and thecontrol valve is a stopcock mounted for rotation on the manifold intothree positions. The system may further include a pressure regulatorlocated between the control valve and the balloon to limit a balloonpressure to a predetermined maximum. Preferably, the pressurized vesselholds air, and the system may further include a piston/cylinder assemblyincorporated into the manifold on which the pressurized air acts andsaline is provided in the system distal to the piston/cylinder assemblyfor inflating the balloon.

A further understanding of the nature and advantages of the presentinvention are set forth in the following description and claims,particularly when considered in conjunction with the accompanyingdrawings in which like parts bear like reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained and other advantages and featureswill appear with reference to the accompanying schematic drawingswherein:

FIG. 1 is a top plan view of a prosthetic heart valve delivery systemincluding a balloon catheter and introducer combination, with anintegrated inflation system on the proximal end of the balloon catheter;

FIG. 2 shows the prosthetic heart valve delivery system with the ballooncatheter advanced relative to the introducer to position an expansionballoon within a heart valve stent;

FIG. 3 shows inflation of the balloon to expand the heart valve stent byopening communication between a pressure vessel and the balloon; and

FIG. 4 shows deflation of the balloon for withdrawal from within theheart valve stent by opening communication between a vacuum vessel andthe balloon.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present application discloses an integrated inflation system for aballoon catheter. The inflation system can be coupled to any type ofballoon catheter, including but not limited to those used forangioplasty, vascular stent expansion, or as in the illustratedembodiment, expansion of a prosthetic heart valve stent. The term“integrated” refers to a manufactured assembly of components that enablerapid inflation and deflation of the balloon of the catheter. Anintegrated system is not simply an assembly of components, but rathercomponents that have been pre-assembled during the fabrication processso that they are packaged and sold as a single, unitary system. In thissense, “integrated” contemplates systems that are pre-assembled as oneproduct, and packaged and stored in a unique enclosure as opposed to twoor more. Thus, an integrated system arrives at the operating sitecomplete with no further connections needed. The components may be“permanently” joined together, such as by being adhered or thermalwelded together so that they cannot be separated without damaging thesystem, though the components can also be connected together throughless permanent means such as with threaded connectors or the like. Other“permanent” connections include a configuration where the components aremolded together as one piece, or where some components are “within”larger components, such as where a pressure vessel is positioned withina manifold. Of course, “permanently” connecting components does not meanthat they cannot ever be separated, such as with brute force, but ratherthat they are not intended to be separated and that separation willdamage their ready functionality in some way.

FIG. 1 illustrates a prosthetic heart valve delivery system 20 having anintegrated inflation system 22 on the proximal end of a balloon catheter24 which terminates on a distal end in an expandable balloon 26. In theillustrated system 20, the balloon catheter 24 slides linearly within ahandpiece of an introducer 28. The introducer 28 also has a malleablehandle shaft 29 leading to a distal locking sleeve 30. The lockingsleeve 30 couples to a valve holder 32 that in turn secures a prostheticheart valve 34 having a distal anchoring stent 36. The entire system hasa length from the proximal end of the inflation system 22 to the tip ofthe balloon 26 that may vary depending on the implant technique. Forexample, devices for surgical valve replacement require relatively shortcatheters, perhaps between about 200 and 400 mm. On the other hand,so-called “direct-access” devices for beating heart surgeries enter thebody through a port in the chest and are routed essentially directly tothe heart, requiring somewhat longer catheters, perhaps 300 to 600 mm.Finally, transfemoral deliveries that enter through the leg and passthrough the vasculature require much longer catheters, often between100-200 cm.

The balloon 26 is initially retracted within the introducer 28 and heartvalve 34, and distal movement of the balloon catheter 24 as seen in FIG.2 moves the balloon 26 into a predetermined position to enable expansionof the heart valve stent 36. As will be explained, inflation of theballoon 26 expands the heart valve stent 36 outward into contact withsurrounding anatomy. The prosthetic heart valve delivery system 20 isparticularly well-suited for implanting a prosthetic aortic valve at anaortic annulus, with the stent 36 positioned sub-annularly, against theleft ventricular wall adjacent the aortic valve annulus. Additionaldetails of the exemplary valve deployment system 20 and method of useare disclosed in U.S. Pat. No. 8,641,757, filed Jun. 23, 2011, thecontents of which are expressly incorporated by reference herein. Acommercial system having many of the same components is sold as theEDWARDS INTUITY valve system by Edwards Lifesciences Corp. of Irvine,Calif.

The integrated inflation system 22 includes a junction manifold 38having internal passages and at least three inlet/outlet ports, one ofwhich connects to the proximal end of the balloon catheter 24 (a balloonport). A second inlet/outlet port, or inflation port, of the manifold 38connects to a sealed pressure vessel 40, while a third inlet/outletport, or vacuum port, connects to a sealed vacuum vessel 42. A controlvalve in the form of a stopcock 44 mounted in the manifold 38 controlswhich of the inlet/outlet ports are in fluid communication. In apreferred embodiment the manifold 38 opens to just the balloon port 24,inflation port, and vacuum port, and the control valve is a manualstopcock mounted for rotation on the manifold into three positions. Itshould be understood that the stopcock 44 represents a fluid controlvalve that can be an electromechanical valve having a switch, solenoids,or other such devices, and thus the term “control valve” should not beconsidered limited to a purely mechanical/manual stopcock. The inflationsystem 22 further includes a pressure regulator 46 interposed betweenthe manifold 38 and the balloon catheter 24. The pressure regulator 46functions to sense pressure in the lumen of the balloon catheter 24 andclose upon reaching a threshold pressure.

The particular pressure used to inflate the balloon 26 varies dependingon the application. For instance, the exemplary pressure used in theEDWARDS INTUITY valve system is between about 4.5-5 atmospheres(0.46-0.51 MPa). Other systems may require more or less pressure, suchas up to 7 atm (0.71 MPa), or may utilize a volume based inflationcriteria to achieve a specific diameter. In the latter case, thepressure regulator 46 may be replaced or supplemented with a volumetricflow meter that indicates total volume delivered as opposed to pressure.

FIGS. 3 and 4 illustrate expansion and deflation of the balloon 26 toexpand the anchoring stent 36. Initially, the stopcock is in a neutralposition in between plus (+) and minus (−) signs printed, inscribed orembossed on the manifold 38. The neutral position closes offcommunication between any two ports of the manifold 38. The plus signlies toward the pressure vessel 40, while the minus sign is adjacent tovacuum vessel 42. The plus and minus signs correspond respectively toexpansion/inflation and contraction/deflation of the balloon 26 on theballoon catheter 24. Of course, other indicators such as the colorsgreen and red may be provided on the manifold 38 for the same purpose.Furthermore, the vessels themselves may have the words “Pressure” and“Vacuum” (or Inflate/Deflate) printed, inscribed or embossed thereon, asshown.

FIG. 3 shows the stopcock 44 rotated CCW toward the pressure vessel 40so as to open communication between the pressure vessel and the ballooncatheter 24, thus causing the balloon 26 to inflate and expand,deploying the anchoring stent 36 against the annulus. The anchoringstent 36 transitions between its conical contracted state seen in FIGS.1-2, and its generally tubular or slightly conical expanded state seenin FIGS. 3-4. Simple interference between the anchoring stent 36 and theannulus may be sufficient to anchor the heart valve 34, or interactingfeatures such as projections, hooks, barbs, fabric, etc. may beutilized. Further, the heart valve 34 may have a sealing ring 37 whichcan be secured to the annulus using sutures, barbs, etc.

FIG. 4 shows the stopcock 44 rotated CW toward the vacuum vessel 42which opens communication between the vacuum vessel and the ballooncatheter 24. This communicates a reduced or negative pressure to theinterior of the balloon 26, causing its deflation as shown. Deflation ofthe balloon 26 facilitates its removal from within the heart valve andthe delivery system in general. It should be noted that not all ballooninflation systems require active deflation as shown. In those systems, asimple valve that enables passive deflation of the balloon pressure tothe atmosphere may be provided. The vacuum vessel 42 could thusrepresent such a valve. While that may work with air as the workingfluid, for saline it would be best to deflate the balloon actively.

The exemplary delivery system balloon 26 has a relatively highdiameter-to-length ratio compared to other surgical balloons, such asthose used to expand cardiovascular stents. This makes it particularlydifficult for the balloon 26 to return to a small geometry upondeflation after deployment. Balloons of such size ratios tend to“butterfly” by forming wings that prevent removal through the valve 34and its holder 32 without the application of high forces, which maycause damage to the valve itself. The exemplary balloon 26 thuspreferably includes a series of longitudinal pleats heat set into itswall to facilitate self-collapse during deflation. Further, the distalend of the balloon 26 moves relative to the proximal end to enablelengthening of the balloon during deflation. This lengthening occursautomatically by virtue of an internal wire (not shown) which isspring-biased to stretch the balloon longitudinally. These componentsare also shown in U.S. Pat. No. 8,641,757. It should be noted that easydeflation and removal of the balloon 26 permits rapid replacement of theballoon catheter in case of a problem, such as insufficient inflation.

In the most basic configuration, the integrated inflation system 22 usesair as the working fluid to expand the balloon 26. However, air istypically only compatible for open procedures. In applications wherecontrolled, pressurized, sterile physiologic saline is the workingfluid, the system may require a dynamic piston against which air acts tocause the piston to displace the saline into the balloon 26. One ofskill in the art will understand that such a piston/cylinder assemblycan easily be incorporated into the manifold 38 between the stopcock 44and the pressure regulator 46, such as shown schematically at 50 in FIG.3.

The integrated inflation system 22, and in particular the pressurevessels 40, 42, are manufactured using metallic or polymer-basedcomponents, depending on the pressure loads. Desirably, the system 22 isassembled at the time of manufacture and packaged with the deliverysystem 20. As such, the pressure vessels 40, 42 will be required tomaintain their respective internal pressures over long periods,sometimes years. Consequently, special seals between the pressurevessels 40, 42 and the manifold 38, and between the manifold 38 and theballoon catheter 24, are required. For example, the seals at the outletof a recreational CO₂ cartridge may be suitable. Alternatively, weldedor elastomeric seals which can be punctured or otherwise compromised atthe time of use may be provided. Another solution is to provide a robustvalve at the inlet/outlet of each pressure vessels 40, 42 that can bemanually opened after the system has been removed from its sterilepackaging just prior to use, thus initiating fluid communication betweenthe vessels and the manifold 38 and stopcock 44.

While the invention has been described in its preferred embodiments, itis to be understood that the words which have been used are words ofdescription and not of limitation. Therefore, changes may be made withinthe appended claims without departing from the true scope of theinvention.

What is claimed is:
 1. A method of storing and actuating a ballooncatheter system, comprising: providing an integrated pre-assembledsystem packaged and sold as a single, unitary system in a unique sterileenclosure, the system including: a manifold having internal passages; asealed pressurized vessel permanently attached to an inflation port inthe manifold; a balloon catheter having a balloon on a distal end influid communication with an inflation lumen extending through thecatheter; a balloon port in the manifold in fluid communication with theballoon catheter inflation lumen; and a control valve on the manifoldconfigured to selectively open and close fluid communication between theballoon port and the inflation port so that a positive pressuredifferential from the pressurized vessel inflates the balloon; themethod including: opening the unique sterile enclosure and removing thesystem; advancing the balloon catheter so that the balloon thereon ispositioned at a procedure site within the body; and operating thecontrol valve on the manifold to open fluid communication between theballoon port and the inflation port and inflate the balloon.
 2. Themethod of claim 1, wherein the balloon catheter system is part of aprosthetic heart valve delivery system including a balloon-expandableheart valve crimped onto the balloon, and the step of advancing includespositioning the balloon-expandable heart valve within a native heartvalve annulus.
 3. The method of claim 1, further including a one-wayvalve attached to a deflation port in the manifold, wherein the controlvalve is also configured to selectively open and close fluidcommunication between the balloon port and the deflation port to enablepassive deflation of the balloon pressure to the atmosphere, and themethod includes operating the control valve to open fluid communicationbetween the balloon port and the deflation port after inflating theballoon.
 4. The method of claim 1, wherein the pressurized vessel isattached to the manifold in a manner selected from the group consistingof adhesion and thermal welding.
 5. The method of claim 1, furtherincluding a sealed vacuum vessel permanently attached to a vacuum portin the manifold, wherein the control valve is also configured toselectively open and close fluid communication between the balloon portand the vacuum port so that a negative pressure differential from thevacuum vessel deflates the balloon, and the method includes operatingthe control valve to open fluid communication between the balloon portand the vacuum port after inflating the balloon.
 6. The method of claim5, wherein the manifold opens to just the balloon port, inflation portand vacuum port, and the control valve is a stopcock mounted forrotation on the manifold into three mutually exclusive positions.
 7. Themethod of claim 5, further including provide a valve at an inlet/outletof each of the sealed pressurized vessel and sealed vacuum vessel thatmust be manually opened after the system has been removed from theunique sterile enclosure, thus initiating fluid communication betweenthe vessels and the manifold.
 8. The method of claim 1, furtherincluding a pressure regulator located between the control valve and theballoon to limit a balloon pressure to a predetermined maximum.
 9. Themethod of claim 1, further including an indicator printed, inscribed orembossed on the control valve that conveys information to a userregarding whether there is open fluid communication between the balloonport and the inflation port.
 10. The method of claim 9, wherein theindicator is selected from the group consisting of: a plus sign; and thecolor green.
 11. A method of storing and actuating a balloon cathetersystem, comprising: providing an integrated pre-assembled systempackaged and sold as a single, unitary system in a unique sterileenclosure, the system including: a balloon catheter having a balloon ona distal end in fluid communication with an inflation lumen extendingthrough the catheter; an integrated inflation system having: a manifoldhaving internal passages; a sealed pressurized vessel permanentlyattached to an inflation port in the manifold; a sealed vacuum vesselpermanently attached to a vacuum port in the manifold; a balloon port inthe manifold in fluid communication with the balloon catheter inflationlumen; and a control valve on the manifold configured to selectivelyopen and close fluid communication between the manifold internalpassages and one or the other of the pressurized vessel and vacuumvessel; the method including: opening the unique sterile enclosure andremoving the system; advancing the balloon catheter so that the balloonthereon is positioned at a procedure site within the body; operating thecontrol valve on the manifold to open fluid communication between theballoon port and the inflation port and inflate the balloon; operatingthe control valve on the manifold to close fluid communication betweenthe balloon port and the inflation port and inflate the balloon;operating the control valve on the manifold to open fluid communicationbetween the balloon port and the vacuum port and deflate the balloonafter inflating the balloon; and withdrawing the balloon catheter fromwithin the body.
 12. The method of claim 11, wherein the ballooncatheter system is part of a prosthetic heart valve delivery systemincluding a balloon-expandable heart valve crimped onto the balloon, andthe step of advancing includes positioning the balloon-expandable heartvalve within a native heart valve annulus.
 13. The method of claim 11,further including a one-way valve attached to a deflation port in themanifold, wherein the control valve is also configured to selectivelyopen and close fluid communication between the balloon port and thedeflation port to enable passive deflation of the balloon pressure tothe atmosphere, and the method includes operating the control valve toopen fluid communication between the balloon port and the deflation portafter inflating the balloon.
 14. The method of claim 11, wherein thepressurized vessel is attached to the manifold in a manner selected fromthe group consisting of adhesion and thermal welding.
 15. The method ofclaim 11, wherein the manifold opens to just the balloon port, inflationport and vacuum port, and the control valve is a stopcock mounted forrotation on the manifold into three mutually exclusive positions. 16.The method of claim 11, further including provide a valve at aninlet/outlet of each of the sealed pressurized vessel and sealed vacuumvessel that must be manually opened after the system has been removedfrom the unique sterile enclosure, thus initiating fluid communicationbetween the vessels and the manifold.
 17. The method of claim 11,further including a pressure regulator located between the control valveand the balloon to limit a balloon pressure to a predetermined maximum.18. The method of claim 11, further including an indicator printed,inscribed or embossed on the control valve that conveys information to auser regarding whether there is open fluid communication between theballoon port and the inflation port.
 19. The method of claim 18, whereinthe indicator is selected from the group consisting of: a plus sign; andthe color green.
 20. The method of claim 11, further includingindicators printed, inscribed or embossed on the pressurized vessel andvacuum vessel selected from the group consisting of: the word “Pressure”for the pressurized vessel and the word “Vacuum” for the vacuum vessel;and the word “Inflate” for the pressurized vessel and the word “Deflate”for the vacuum vessel.